Comment 6 for bug 746638

Revision history for this message
Rik Shaw (rik-shaw) wrote :

I believe this is more than a wishlist item. Currently the "Photo" mode will not be adequate for any "non-photograph color document" as the whole document will be gray, and likely any minor imperfections (such as even the paper grain! or maybe a slight crease in the paper) will show strongly (also any text from the backside of the document will likely show through).

In testing with xsane, I see that bumping contrast up to 60% helps to get "white" and also removes imperfections (paper grain, backside text coming through, etc). This probably isn't a great solution as this much contrast adjustment has negatives with regard to color. But, it is much more acceptable for text documents, etc., that have color (and aren't just photographs!).

I would respectfully suggest that there be 2 added scan modes:

1. Mode for grayscale (text) that would give "clean text and white background results"

2. Mode (as suggested here) for color (text) that would give "clean text and white background results".

For many users simple-scan is the only option that they can use well, but it is missing just a few of these abilities that prevent it from being able to stand as the scanner option of choice.

Currently I am testing a "brightness" of 40 and a "contrast" of 60 in xsane and getting decent results.

Linking here to a blueprint for "ensuring white background":

https://blueprints.launchpad.net/simple-scan/+spec/white-background-correction

Also linking a bug suggesting to "add automatic background removal (i.e. alpha channel)":

https://bugs.launchpad.net/simple-scan/+bug/484633

Lastly, not quite as accurate but somewhat related is a bug on color correct scan preview:

https://bugs.launchpad.net/simple-scan/+bug/498029